Re Marlene Dietrich: How about the German version of Where Have All the Flowers Gone? Sag mir, wo die Blumen sind. It may not be popular with young people, but older ones will probably know it, and it's an easy tune.

Which reminds me of one of my favourites, Zogen einst fünf wilde Schwäne - probably derived from the same source as Pete Seeger's song.

Reinhard Mey, Gute Nacht Freunde and Über den Wolken might also go down well.